2006 BMW E60 530xi with water in the fuel system causing the car not to start for the customer. The water has cause the fuel pump module to fail and create a low fuel pressure. The engine will not start due to the cylinders washed down to a lower than normal compression. Technician found the gas cap did not fit the car correctly. Here in the Everett area, we do get a fair amount of rain. The rain water can enter the fuel tank the way very easily. Make sure your fuel cap is tight after fueling to prevent this type of failure.